Clock



FIG. 1 is a perspective view;

FIG. 2 is a front view;

FIG. 3 is a back view;

FIG. 4 is a right side view;

FIG. 5 is a left side view;

FIG. 6 is a top view; and,

FIG. 7 is a bottom view. 

The ornamental design for a clock, as shown. 